* KASAN: use-after-free Read in line6_submit_audio_in_all_urbs
@ 2020-06-26 17:18 syzbot
2020-06-26 18:26 ` Alan Stern
0 siblings, 1 reply; 5+ messages in thread
From: syzbot @ 2020-06-26 17:18 UTC (permalink / raw)
To: alsa-devel, andreyknvl, linux-kernel, linux-usb, perex,
syzkaller-bugs, tiwai
Hello,
syzbot found the following crash on:
HEAD commit: fb574682 usbip: tools: fix module name in man page
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
console output: https://syzkaller.appspot.com/x/log.txt?x=156560b1100000
kernel config: https://syzkaller.appspot.com/x/.config?x=63b40b2ae167bad6
dashboard link: https://syzkaller.appspot.com/bug?extid=145012a46658ac00fc9e
compiler: gcc (GCC) 10.1.0-syz 20200507
Unfortunately, I don't have any reproducer for this crash yet.
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+145012a46658ac00fc9e@syzkaller.appspotmail.com
snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
==================================================================
BUG: KASAN: use-after-free in line6_submit_audio_in_all_urbs+0x10b/0x120 sound/usb/line6/capture.c:72
Read of size 8 at addr ffff8881cffb1800 by task kworker/1:5/3257
CPU: 1 PID: 3257 Comm: kworker/1:5 Not tainted 5.8.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events line6_startup_work
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xf6/0x16e lib/dump_stack.c:118
print_address_description.constprop.0+0x1a/0x210 mm/kasan/report.c:383
__kasan_report mm/kasan/report.c:513 [inline]
kasan_report.cold+0x37/0x7c mm/kasan/report.c:530
line6_submit_audio_in_all_urbs+0x10b/0x120 sound/usb/line6/capture.c:72
line6_stream_start+0x207/0x230 sound/usb/line6/pcm.c:197
line6_pcm_acquire+0x161/0x210 sound/usb/line6/pcm.c:318
line6_startup_work+0x42/0x50 sound/usb/line6/driver.c:734
process_one_work+0x94c/0x15f0 kernel/workqueue.c:2269
worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
kthread+0x392/0x470 kernel/kthread.c:291
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
Allocated by task 76:
save_stack+0x1b/0x40 mm/kasan/common.c:48
set_track mm/kasan/common.c:56 [inline]
__kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494
kmalloc include/linux/slab.h:555 [inline]
kzalloc include/linux/slab.h:669 [inline]
line6_init_pcm+0x2a7/0x9e0 sound/usb/line6/pcm.c:533
toneport_init+0xdd/0x6b0 sound/usb/line6/toneport.c:419
line6_probe+0xaa0/0x1330 sound/usb/line6/driver.c:809
usb_probe_interface+0x315/0x7f0 drivers/usb/core/driver.c:374
really_probe+0x291/0xc90 drivers/base/dd.c:525
driver_probe_device+0x26b/0x3d0 drivers/base/dd.c:701
__device_attach_driver+0x1d1/0x290 drivers/base/dd.c:807
bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:431
__device_attach+0x28d/0x430 drivers/base/dd.c:873
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491
device_add+0xb09/0x1b40 drivers/base/core.c:2680
usb_set_configuration+0xf05/0x18a0 drivers/usb/core/message.c:2032
usb_generic_driver_probe+0xba/0xf2 drivers/usb/core/generic.c:241
usb_probe_device+0xd9/0x250 drivers/usb/core/driver.c:272
really_probe+0x291/0xc90 drivers/base/dd.c:525
driver_probe_device+0x26b/0x3d0 drivers/base/dd.c:701
__device_attach_driver+0x1d1/0x290 drivers/base/dd.c:807
bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:431
__device_attach+0x28d/0x430 drivers/base/dd.c:873
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491
device_add+0xb09/0x1b40 drivers/base/core.c:2680
usb_new_device.cold+0x71d/0xfd4 drivers/usb/core/hub.c:2554
hub_port_connect drivers/usb/core/hub.c:5208 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5348 [inline]
port_event drivers/usb/core/hub.c:5494 [inline]
hub_event+0x2361/0x4390 drivers/usb/core/hub.c:5576
process_one_work+0x94c/0x15f0 kernel/workqueue.c:2269
worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
kthread+0x392/0x470 kernel/kthread.c:291
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
Freed by task 3044:
save_stack+0x1b/0x40 mm/kasan/common.c:48
set_track mm/kasan/common.c:56 [inline]
kasan_set_free_info mm/kasan/common.c:316 [inline]
__kasan_slab_free+0x116/0x160 mm/kasan/common.c:455
slab_free_hook mm/slub.c:1474 [inline]
slab_free_freelist_hook+0x53/0x140 mm/slub.c:1507
slab_free mm/slub.c:3072 [inline]
kfree+0xbc/0x2c0 mm/slub.c:4063
snd_pcm_free sound/core/pcm.c:865 [inline]
snd_pcm_dev_free+0x67/0xb0 sound/core/pcm.c:876
__snd_device_free+0x19f/0x300 sound/core/device.c:76
snd_device_free_all+0xef/0x20d sound/core/device.c:233
snd_card_do_free sound/core/init.c:472 [inline]
release_card_device+0x1b/0xd0 sound/core/init.c:140
device_release+0x71/0x200 drivers/base/core.c:1559
kobject_cleanup lib/kobject.c:693 [inline]
kobject_release lib/kobject.c:722 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x245/0x540 lib/kobject.c:739
put_device+0x1b/0x30 drivers/base/core.c:2779
snd_card_free_when_closed+0x35/0x50 sound/core/init.c:499
line6_disconnect.cold+0xa4/0xbd sound/usb/line6/driver.c:860
usb_unbind_interface+0x1d8/0x8d0 drivers/usb/core/driver.c:436
__device_release_driver+0x3b7/0x6e0 drivers/base/dd.c:1113
device_release_driver_internal drivers/base/dd.c:1144 [inline]
device_release_driver+0x26/0x40 drivers/base/dd.c:1167
bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:533
device_del+0x47c/0xd20 drivers/base/core.c:2857
usb_disable_device+0x387/0x930 drivers/usb/core/message.c:1245
usb_disconnect.cold+0x27d/0x780 drivers/usb/core/hub.c:2217
hub_port_connect drivers/usb/core/hub.c:5059 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5348 [inline]
port_event drivers/usb/core/hub.c:5494 [inline]
hub_event+0x1c93/0x4390 drivers/usb/core/hub.c:5576
process_one_work+0x94c/0x15f0 kernel/workqueue.c:2269
worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
kthread+0x392/0x470 kernel/kthread.c:291
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
The buggy address belongs to the object at ffff8881cffb1800
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 0 bytes inside of
1024-byte region [ffff8881cffb1800, ffff8881cffb1c00)
The buggy address belongs to the page:
page:ffffea00073fec00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 head:ffffea00073fec00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x200000000010200(slab|head)
raw: 0200000000010200 ffffea00074f0c00 0000000300000003 ffff8881da002280
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8881cffb1700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8881cffb1780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8881cffb1800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881cffb1880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881cffb1900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: KASAN: use-after-free Read in line6_submit_audio_in_all_urbs
2020-06-26 17:18 KASAN: use-after-free Read in line6_submit_audio_in_all_urbs syzbot
@ 2020-06-26 18:26 ` Alan Stern
0 siblings, 0 replies; 5+ messages in thread
From: Alan Stern @ 2020-06-26 18:26 UTC (permalink / raw)
To: syzbot
Cc: alsa-devel, andreyknvl, linux-usb, syzkaller-bugs, linux-kernel,
tiwai
On Fri, Jun 26, 2020 at 10:18:12AM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: fb574682 usbip: tools: fix module name in man page
> git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
> console output: https://syzkaller.appspot.com/x/log.txt?x=156560b1100000
> kernel config: https://syzkaller.appspot.com/x/.config?x=63b40b2ae167bad6
> dashboard link: https://syzkaller.appspot.com/bug?extid=145012a46658ac00fc9e
> compiler: gcc (GCC) 10.1.0-syz 20200507
>
> Unfortunately, I don't have any reproducer for this crash yet.
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+145012a46658ac00fc9e@syzkaller.appspotmail.com
>
> snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
> snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
> snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
> snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
> ==================================================================
> BUG: KASAN: use-after-free in line6_submit_audio_in_all_urbs+0x10b/0x120 sound/usb/line6/capture.c:72
> Read of size 8 at addr ffff8881cffb1800 by task kworker/1:5/3257
>
> CPU: 1 PID: 3257 Comm: kworker/1:5 Not tainted 5.8.0-rc1-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Workqueue: events line6_startup_work
> Call Trace:
> __dump_stack lib/dump_stack.c:77 [inline]
> dump_stack+0xf6/0x16e lib/dump_stack.c:118
> print_address_description.constprop.0+0x1a/0x210 mm/kasan/report.c:383
> __kasan_report mm/kasan/report.c:513 [inline]
> kasan_report.cold+0x37/0x7c mm/kasan/report.c:530
> line6_submit_audio_in_all_urbs+0x10b/0x120 sound/usb/line6/capture.c:72
> line6_stream_start+0x207/0x230 sound/usb/line6/pcm.c:197
> line6_pcm_acquire+0x161/0x210 sound/usb/line6/pcm.c:318
> line6_startup_work+0x42/0x50 sound/usb/line6/driver.c:734
> process_one_work+0x94c/0x15f0 kernel/workqueue.c:2269
> worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
> kthread+0x392/0x470 kernel/kthread.c:291
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
>
> Allocated by task 76:
> save_stack+0x1b/0x40 mm/kasan/common.c:48
> set_track mm/kasan/common.c:56 [inline]
> __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494
> kmalloc include/linux/slab.h:555 [inline]
> kzalloc include/linux/slab.h:669 [inline]
> line6_init_pcm+0x2a7/0x9e0 sound/usb/line6/pcm.c:533
> toneport_init+0xdd/0x6b0 sound/usb/line6/toneport.c:419
> line6_probe+0xaa0/0x1330 sound/usb/line6/driver.c:809
It look like the cancel_delayed_work() in line6_disconnect() needs to be
cancel_delayed_work_sync(). Unfortunately we can't test this until syzbot
is able to reproduce the bug.
Alan Stern
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: KASAN: use-after-free Read in line6_submit_audio_in_all_urbs
@ 2020-06-26 18:26 ` Alan Stern
0 siblings, 0 replies; 5+ messages in thread
From: Alan Stern @ 2020-06-26 18:26 UTC (permalink / raw)
To: syzbot
Cc: alsa-devel, andreyknvl, linux-kernel, linux-usb, perex,
syzkaller-bugs, tiwai
On Fri, Jun 26, 2020 at 10:18:12AM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: fb574682 usbip: tools: fix module name in man page
> git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
> console output: https://syzkaller.appspot.com/x/log.txt?x=156560b1100000
> kernel config: https://syzkaller.appspot.com/x/.config?x=63b40b2ae167bad6
> dashboard link: https://syzkaller.appspot.com/bug?extid=145012a46658ac00fc9e
> compiler: gcc (GCC) 10.1.0-syz 20200507
>
> Unfortunately, I don't have any reproducer for this crash yet.
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+145012a46658ac00fc9e@syzkaller.appspotmail.com
>
> snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
> snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
> snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
> snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
> ==================================================================
> BUG: KASAN: use-after-free in line6_submit_audio_in_all_urbs+0x10b/0x120 sound/usb/line6/capture.c:72
> Read of size 8 at addr ffff8881cffb1800 by task kworker/1:5/3257
>
> CPU: 1 PID: 3257 Comm: kworker/1:5 Not tainted 5.8.0-rc1-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Workqueue: events line6_startup_work
> Call Trace:
> __dump_stack lib/dump_stack.c:77 [inline]
> dump_stack+0xf6/0x16e lib/dump_stack.c:118
> print_address_description.constprop.0+0x1a/0x210 mm/kasan/report.c:383
> __kasan_report mm/kasan/report.c:513 [inline]
> kasan_report.cold+0x37/0x7c mm/kasan/report.c:530
> line6_submit_audio_in_all_urbs+0x10b/0x120 sound/usb/line6/capture.c:72
> line6_stream_start+0x207/0x230 sound/usb/line6/pcm.c:197
> line6_pcm_acquire+0x161/0x210 sound/usb/line6/pcm.c:318
> line6_startup_work+0x42/0x50 sound/usb/line6/driver.c:734
> process_one_work+0x94c/0x15f0 kernel/workqueue.c:2269
> worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
> kthread+0x392/0x470 kernel/kthread.c:291
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
>
> Allocated by task 76:
> save_stack+0x1b/0x40 mm/kasan/common.c:48
> set_track mm/kasan/common.c:56 [inline]
> __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494
> kmalloc include/linux/slab.h:555 [inline]
> kzalloc include/linux/slab.h:669 [inline]
> line6_init_pcm+0x2a7/0x9e0 sound/usb/line6/pcm.c:533
> toneport_init+0xdd/0x6b0 sound/usb/line6/toneport.c:419
> line6_probe+0xaa0/0x1330 sound/usb/line6/driver.c:809
It look like the cancel_delayed_work() in line6_disconnect() needs to be
cancel_delayed_work_sync(). Unfortunately we can't test this until syzbot
is able to reproduce the bug.
Alan Stern
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: KASAN: use-after-free Read in line6_submit_audio_in_all_urbs
2020-06-26 18:26 ` Alan Stern
@ 2020-07-10 13:59 ` Takashi Iwai
-1 siblings, 0 replies; 5+ messages in thread
From: Takashi Iwai @ 2020-07-10 13:59 UTC (permalink / raw)
To: Alan Stern
Cc: alsa-devel, syzbot, andreyknvl, linux-usb, syzkaller-bugs,
linux-kernel, tiwai
On Fri, 26 Jun 2020 20:26:05 +0200,
Alan Stern wrote:
>
> On Fri, Jun 26, 2020 at 10:18:12AM -0700, syzbot wrote:
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit: fb574682 usbip: tools: fix module name in man page
> > git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
> > console output: https://syzkaller.appspot.com/x/log.txt?x=156560b1100000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=63b40b2ae167bad6
> > dashboard link: https://syzkaller.appspot.com/bug?extid=145012a46658ac00fc9e
> > compiler: gcc (GCC) 10.1.0-syz 20200507
> >
> > Unfortunately, I don't have any reproducer for this crash yet.
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+145012a46658ac00fc9e@syzkaller.appspotmail.com
> >
> > snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
> > snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
> > snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
> > snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
> > ==================================================================
> > BUG: KASAN: use-after-free in line6_submit_audio_in_all_urbs+0x10b/0x120 sound/usb/line6/capture.c:72
> > Read of size 8 at addr ffff8881cffb1800 by task kworker/1:5/3257
> >
> > CPU: 1 PID: 3257 Comm: kworker/1:5 Not tainted 5.8.0-rc1-syzkaller #0
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> > Workqueue: events line6_startup_work
> > Call Trace:
> > __dump_stack lib/dump_stack.c:77 [inline]
> > dump_stack+0xf6/0x16e lib/dump_stack.c:118
> > print_address_description.constprop.0+0x1a/0x210 mm/kasan/report.c:383
> > __kasan_report mm/kasan/report.c:513 [inline]
> > kasan_report.cold+0x37/0x7c mm/kasan/report.c:530
> > line6_submit_audio_in_all_urbs+0x10b/0x120 sound/usb/line6/capture.c:72
> > line6_stream_start+0x207/0x230 sound/usb/line6/pcm.c:197
> > line6_pcm_acquire+0x161/0x210 sound/usb/line6/pcm.c:318
> > line6_startup_work+0x42/0x50 sound/usb/line6/driver.c:734
> > process_one_work+0x94c/0x15f0 kernel/workqueue.c:2269
> > worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
> > kthread+0x392/0x470 kernel/kthread.c:291
> > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
> >
> > Allocated by task 76:
> > save_stack+0x1b/0x40 mm/kasan/common.c:48
> > set_track mm/kasan/common.c:56 [inline]
> > __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494
> > kmalloc include/linux/slab.h:555 [inline]
> > kzalloc include/linux/slab.h:669 [inline]
> > line6_init_pcm+0x2a7/0x9e0 sound/usb/line6/pcm.c:533
> > toneport_init+0xdd/0x6b0 sound/usb/line6/toneport.c:419
> > line6_probe+0xaa0/0x1330 sound/usb/line6/driver.c:809
>
> It look like the cancel_delayed_work() in line6_disconnect() needs to be
> cancel_delayed_work_sync(). Unfortunately we can't test this until syzbot
> is able to reproduce the bug.
Right, but fixing it now wouldn't be bad.
The fix patch below.
thanks,
Takashi
-- 8< --
From: Takashi Iwai <tiwai@suse.de>
Subject: [PATCH] ALSA: line6: Sync the pending work cancel at disconnection
Recently syzkaller reported a UAF in LINE6 driver, and it's likely
because we call cancel_delayed_work() at the disconnect callback
instead of cancel_delayed_work_sync(). Let's use the correct one
instead.
Reported-by: syzbot+145012a46658ac00fc9e@syzkaller.appspotmail.com
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
sound/usb/line6/driver.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/usb/line6/driver.c b/sound/usb/line6/driver.c
index 7629116f570e..2746d9698180 100644
--- a/sound/usb/line6/driver.c
+++ b/sound/usb/line6/driver.c
@@ -840,7 +840,7 @@ void line6_disconnect(struct usb_interface *interface)
if (WARN_ON(usbdev != line6->usbdev))
return;
- cancel_delayed_work(&line6->startup_work);
+ cancel_delayed_work_sync(&line6->startup_work);
if (line6->urb_listen != NULL)
line6_stop_listen(line6);
--
2.16.4
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: KASAN: use-after-free Read in line6_submit_audio_in_all_urbs
@ 2020-07-10 13:59 ` Takashi Iwai
0 siblings, 0 replies; 5+ messages in thread
From: Takashi Iwai @ 2020-07-10 13:59 UTC (permalink / raw)
To: Alan Stern
Cc: syzbot, alsa-devel, andreyknvl, linux-usb, syzkaller-bugs,
linux-kernel, tiwai
On Fri, 26 Jun 2020 20:26:05 +0200,
Alan Stern wrote:
>
> On Fri, Jun 26, 2020 at 10:18:12AM -0700, syzbot wrote:
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit: fb574682 usbip: tools: fix module name in man page
> > git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
> > console output: https://syzkaller.appspot.com/x/log.txt?x=156560b1100000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=63b40b2ae167bad6
> > dashboard link: https://syzkaller.appspot.com/bug?extid=145012a46658ac00fc9e
> > compiler: gcc (GCC) 10.1.0-syz 20200507
> >
> > Unfortunately, I don't have any reproducer for this crash yet.
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+145012a46658ac00fc9e@syzkaller.appspotmail.com
> >
> > snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
> > snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
> > snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
> > snd_usb_toneport 5-1:0.0: URB in #0 submission failed (-19)
> > ==================================================================
> > BUG: KASAN: use-after-free in line6_submit_audio_in_all_urbs+0x10b/0x120 sound/usb/line6/capture.c:72
> > Read of size 8 at addr ffff8881cffb1800 by task kworker/1:5/3257
> >
> > CPU: 1 PID: 3257 Comm: kworker/1:5 Not tainted 5.8.0-rc1-syzkaller #0
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> > Workqueue: events line6_startup_work
> > Call Trace:
> > __dump_stack lib/dump_stack.c:77 [inline]
> > dump_stack+0xf6/0x16e lib/dump_stack.c:118
> > print_address_description.constprop.0+0x1a/0x210 mm/kasan/report.c:383
> > __kasan_report mm/kasan/report.c:513 [inline]
> > kasan_report.cold+0x37/0x7c mm/kasan/report.c:530
> > line6_submit_audio_in_all_urbs+0x10b/0x120 sound/usb/line6/capture.c:72
> > line6_stream_start+0x207/0x230 sound/usb/line6/pcm.c:197
> > line6_pcm_acquire+0x161/0x210 sound/usb/line6/pcm.c:318
> > line6_startup_work+0x42/0x50 sound/usb/line6/driver.c:734
> > process_one_work+0x94c/0x15f0 kernel/workqueue.c:2269
> > worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
> > kthread+0x392/0x470 kernel/kthread.c:291
> > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
> >
> > Allocated by task 76:
> > save_stack+0x1b/0x40 mm/kasan/common.c:48
> > set_track mm/kasan/common.c:56 [inline]
> > __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494
> > kmalloc include/linux/slab.h:555 [inline]
> > kzalloc include/linux/slab.h:669 [inline]
> > line6_init_pcm+0x2a7/0x9e0 sound/usb/line6/pcm.c:533
> > toneport_init+0xdd/0x6b0 sound/usb/line6/toneport.c:419
> > line6_probe+0xaa0/0x1330 sound/usb/line6/driver.c:809
>
> It look like the cancel_delayed_work() in line6_disconnect() needs to be
> cancel_delayed_work_sync(). Unfortunately we can't test this until syzbot
> is able to reproduce the bug.
Right, but fixing it now wouldn't be bad.
The fix patch below.
thanks,
Takashi
-- 8< --
From: Takashi Iwai <tiwai@suse.de>
Subject: [PATCH] ALSA: line6: Sync the pending work cancel at disconnection
Recently syzkaller reported a UAF in LINE6 driver, and it's likely
because we call cancel_delayed_work() at the disconnect callback
instead of cancel_delayed_work_sync(). Let's use the correct one
instead.
Reported-by: syzbot+145012a46658ac00fc9e@syzkaller.appspotmail.com
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
sound/usb/line6/driver.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/usb/line6/driver.c b/sound/usb/line6/driver.c
index 7629116f570e..2746d9698180 100644
--- a/sound/usb/line6/driver.c
+++ b/sound/usb/line6/driver.c
@@ -840,7 +840,7 @@ void line6_disconnect(struct usb_interface *interface)
if (WARN_ON(usbdev != line6->usbdev))
return;
- cancel_delayed_work(&line6->startup_work);
+ cancel_delayed_work_sync(&line6->startup_work);
if (line6->urb_listen != NULL)
line6_stop_listen(line6);
--
2.16.4
^ permalink raw reply related [flat|nested] 5+ messages in thread
end of thread, other threads:[~2020-07-10 14:01 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2020-06-26 17:18 KASAN: use-after-free Read in line6_submit_audio_in_all_urbs syzbot
2020-06-26 18:26 ` Alan Stern
2020-06-26 18:26 ` Alan Stern
2020-07-10 13:59 ` Takashi Iwai
2020-07-10 13:59 ` Takashi Iwai
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